2013-04-10_GENERAL DOCUMENTS - C1981019

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Soils information is found in Section B, Item IV of this document, as well as in Section 2.04.9 and Exhibit 9 of the PAP original volumes. Soils information associated with the PR -02 South Taylor and Lower Wilson expansion areas is included in Section 2.04.9 of Volume 12, Exhibit 9 of Volume 13, and Maps 5A, 513, and 5C of Volume 14. Soils information associated with PR- 03, Collom expansion, are found in Exhibit 9, Item 8, and Map 5D. The most prevalent soils within the proposed Collom disturbance area are the Duffymont - Nortez complex. The Duffymont soil ranges from 6 to 20 inches available for topsoil salvage, and is formed in slope alluvium and colluviums over sandstone bedrock. Nortez soils tend to be deeper and are found in the loess deposited over alluvial materials. Salvageble depths for Nortez soils range from 20 to 40 inches. The Thornburgh - Lithic Haplocryoll soil complex is found on steeper side - slopes. The Thornburgh series tends to be poorly developed, with 12 inches or less potentially available for topsoil salvage. 3.2.8 Ground Water Hydrology Ground water information is found in Sections 2.04.5, 2.04.7 (Volume 1 for the East Pit, West Pit, Section 16 Pit, Facilities Area and Gossard Loadout, Volume 12 for South Taylor, and Volume 15 for Collom expansion) and Exhibit 7 of the PAP and in Colowyo's Annual Hydrologic Reports. Ground water in the permit area occurs in beds of fractured sandstone and coal that are laterally discontinuous and in isolated alluvial aquifers. The operator refers to alluvial water - bearing units in the Collom area as "valley fill ". Base flow in the four perennial streams in the general area (Good Spring Creek, Wilson Creek, Collom Gulch and Jubb Creek) comes mainly from ground water discharge from alluvial aquifers in the stream valleys. The Trout Creek Sandstone is the principal regional aquifer in the area. It is approximately 400 feet beneath the lowest coal seam to be mined in the Collom area. The principal recharge area for the Trout Creek Sandstone is in the outcrop belt on the north slope of Wilson Dome, south of the permit area. The Trout Creek Sandstone outcrops north of the permit area, where ground water is discharged at the surface. The Mancos Shale underlies the Iles Formation and forms the base of the regional ground water system in the area. This shale is exposed at the surface north of the permit area, in the southern limb of the Axial Basin Anticline. Due to the impervious nature of the Mancos Shale, ground water flow in either the deep bedrock units of the Williams Fork and Iles Formations or the alluvial aquifers of Goodspring Creek and Wilson Creek is discharged to the streams where they flow across the Mancos Shale. 3.2.9 Surface Water Hydrology Surface water information is found in Sections 2.04.7 and 4.05 (Volume 1 for the East Pit, West Pit, Section 16 Pit, Facilities Area and Gossard Loadout, Volume 12 for South Taylor and Volume 15 for Collom expansion); Maps 11, 11A, 12, 12A, 32 and 37; and Exhibit 7 of the PAP. Surface water information for the South Taylor and Lower Wilson areas can be found in Section 2.04.7(2) Surface Water Resource Information and Section 4.05 Hydrologic Balance in Volume Colowyo Coal Mine C1981 -019 PR -03 24 April 10, 2013